紧邻在建主楼桩基的地下室基坑围护设计实例

A real case of retaining structure design for basement excavation near to buildings in construction

该文介绍了一个紧邻在建主桩基的地下室基坑围护设计的实例。通过对工期、施工空间、安全性以及造价的综合分析,确定了以土钉墙为主的围护方式。通过有限元计算对开挖所造成的主楼桩基与地基土的相互作用机理的分析, 表明桩对土的约束作用限制在一定的范围内。根据分析结果,在设计中采用比较大的安全系数以及开挖前的超前支护结构以控制开挖过程中主楼基础地板下地基土的侧向位移,最大限度地减少由于地下室开挖卸载而造成的主动土压力对已有主楼桩基的影响,保证在地下室开挖过程中主楼的施工安全,同时也保证了地下室已有桩基的安全。实践证明,这种方法是有效的,对同类工程的围护设计具有一定的借鉴价值。

A real case of retaining structure design for basement excavation near to buildings in constructing is introduced in this paper. The retaining structure of a kind of special soil - nailed wall is provided after comparison with other retaining structures in the aspects of time limit, construction space, safety and economy. A FEM model is built and used to analyze the interaction between the piles and soil. In the design,a bigger safety index and a king of fore - retaining structure are used to control the lateral displacement of soil under the buildings in construction during excavation, to reduce the influence of unloading caused by excavation on the pile foundation of near buildings in construction, and to ensure the safety of pile foundation of basement. This design is proved good by practice and is valuable for the retaining, structure design for similar projects.